Will an atom emit light if all the atoms electrons are in the ground state

What is the maximum acceleration of the wing tips, in units of g?

In the image, the arrow is pointing to a celestial object. which attribute disqualifies the object from being a planet?

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90